a list of BaseGenericMutantOperator objects.
a list of BaseGenericMutantOperator objects.
Message object that has on of on-demand style message object.
Message object that has on of on-demand style message object.
Runner object that is executed when engine starts.
Runner object that is executed when engine starts.
:: ApplicationDeveloperApi ::
Controller that pipelines data from operator to operators. This controll is triggered when query has been arrived and pipelines a series of subsequent operators.